The ultimate home solar deals site just launched. Three and a half year old data startup Geostellar has finally launched a free website, and a mobile app, that enable anyone to type in a U.S. address to see how much rooftop solar panels would cost on a building, how much power they’d produce, and what deals are out there.

Creating a simple site to do just that — act as a sort of Orbitz for solar — is harder than it sounds. Solar rooftops only really work well in specific environments where there’s enough sun, where there’s a roof with the right tilt, and where there’s a state or city with strong subsidies.

Geostellar’s system, called Solar Mojo for consumers, pulls in data from dozens of sources to create an accurate estimate and also one that incorporates what deals are available in your area from solar installers like SolarCity and financiers like Clean Power Finance. After you type in an address, you can see how much it would cost to buy solar panels outright, or lease them through a deal. You can also see what tax rebates, and local and federal incentives are available to you.

Anyone who’s purchased solar panels knows that getting them is a complex process. So it’s great that a startup can use big data tools and the Internet to make the process easier and less confusing.

For solar installers and financiers — which are Geostellars main customers — the free site can act as a lead generator. Because solar panel prices have dropped so dramatically in recent years, competition is fierce between vendors and lead-gen is very valuable.